Shared Illusions(Delusions)

Recently, one of my readership raised a note-worthy question. Paraphrased, the question was this: Can two people share illusions. Personally, I think delusions is a better word choice. But at any rate, the answer, I believe, is a resounding yes, two people can most certainly share an illusion/delusion, but I contend that not only two people can take part in this, but thousands, even millions, can. But let's deal with an example of the former, first(two people):

 There was a popular board game when I was growing up called the "Ouija Board", or sometimes called, a Spiritual Board, which is a board game that consists of a flat board with the alphabet and the numerals 0-9 on it, along with the words "yes", "no", and "goodbye" on it. On a few versions, there are also some artsy "mystical" symbols on it such as the ever-popular pentagram and half moon, which I suppose sets the mood for what's (supposedly) about to come. There is also a plastic or wooden indicator by which the "spirits"(be they good, or evil) presumably communicate, speaking through the players as "mediums" by pointing to letters/numbers/words to get their "message" across, during what's called a "séance". In a nutshell, players place their fingers(hint) on the indicator, then ask the "spirit world" questions in the hopes that a disembodied "person"(AKA "spirit") will answer. 

Next: A Bigger Game

How about an example of tens of thousands of people sharing an "illusion"? I speak of the the Marian Apparitions(of Fatima). To encapsulate, this is where 3 Shepherd children in Portugal were reportedly visited by an angel. The angelic visits where allegedly to prepare the children for visitations by the "Blessed Mother" starting in 1917. In July of that year, the "The Virgin Mary", herself, purportedly promised that there would be a "miracle" on October 13 so that all would believe. 

On October of that year, a crowd as big as 70,000 people showed up to see the event. There were reporters and photographers, as well. Once the rain had subsided, it was reported that the sun "danced" in the sky. This, believers contend, was the "miracle"..i.e..the evidence that, in fact, "The Blessed Mother" did keep her promise.

Now, what in tarnation is really going on, here? Tell me something, on list of what mostly likely happened in the above-cited examples, do you put talking "spirits", "angels", "demons", and "virgin" ghosts on the top of that list??? Or are those things at the very bottom of the list? I mean, how can two people, and especially thousands of people, be wrong and deluded?  Just how is this possible?

Here's how: 

Regarding the first example, the two playing the Ouija Board go into it EXPECTING to communicate with dead people. An expectation is the first ginormous hint that the ordeal will contain partiality. The next elephant-sized hint is that the participants are touching the indicator. Duh? Hello? Next, factor in that, since one player probably doesn't want the other player to feel let down, that, in all likelihood, he or she would then be willing to consciously move the indicator, and naturally, this would convince the other player that "spirits" are speaking through them. 

Last but not least, there is the "ideomotor effect", and this is where the subject makes motions unconsciously, and in the case of the Ouija Board, they move their hand unconsciously. For instance, like under certain conditions when tears are shed, this isn't done consciously, but unconsciously.
 
Regarding the second example, the 70,000 people are EXPECTING to see a "miracle". After all, their "faith" depends on it. Next, consider that they are hot, dehydrated from waiting outside, and most of all, they are looking...where? Why of course, they're looking directly into the flippin' SUN, just as they were instructed to do. 

Now, isn't it highly likely that staring directly into the sun(since it can cause blindness, after all) can cause hallucinations? And perhaps most importantly, why didn't any of the rest of the world's population see this event? Hmmmm.....

Poor, poor Mother Mary. Whatever will she do with her gullible children?